In-line connector terminals for implantable medical electrical leads

An implantable medical electrical lead comprising an elongate insulative body, a plurality of electrodes mounted to a distal portion of the body, an in-line connector terminal extending from a proximal end of the body, and a corresponding plurality of elongate conductors extending within the body between the electrodes and the in-line connector terminal, the in-line connector terminal including a strut member, a contact pin, a plurality of contact members and a corresponding plurality of insulator members, the contact pin terminating a proximal end of the connector terminal and being engaged within a proximal end of the strut member and coupled to a distal-most electrode of the plurality of electrodes by a first conductor of the plurality of elongate conductors, the first conductor extending through a lumen of the strut member, the lumen defining a central longitudinal axis of the in-line connector terminal, and the plurality of contact members and insulator members being mounted on the strut member such that each insulator member is positioned between adjacent contact members, and the improvement comprising:

• each contact member being coupled to a corresponding electrode of the plurality of electrodes by a corresponding peripheral conductor of the plurality of elongate conductors, each peripheral conductor extending continuously from a distal junction with the corresponding electrode to a proximal junction with the corresponding contact member of the in-line connector terminal;
• and
• each proximal junction being formed by:
• a conductive coupling between a conductive sleeve and the corresponding peripheral conductor;
• a fitting of the conductive coupling within an eyelet feature of the contact member, the eyelet feature extending from an inner surface of the contact member toward the central longitudinal axis of the connector terminal;
• and
• a weld joint between the fitted conductive coupling and an external recessed surface of the contact member, the weld joint being located at a pre-formed slot of the contact member, the pre-formed slot exposing the conductive sleeve of the fitted conductive coupling and extending from an edge of the contact member and along the external recessed surface;
• wherein each weld joint is overlaid by a corresponding insulator member of the plurality of insulator members.

A method for assembling an in-line connector terminal to complete construction of an implantable medical electrical lead, the lead including an elongate insulative body, a plurality of elongate peripheral conductors, and a plurality of electrodes, each conductor extending within the body and having a proximal portion extending out from a proximal end of the body, each electrode being mounted to a distal portion of the elongate body, each of the of the plurality of electrodes being coupled to a corresponding conductor of the plurality of peripheral conductors, and the method comprising:

• coupling each of a plurality of conductive sleeves to the proximal portion of the corresponding conductor of the plurality of peripheral conductors such that each conductive sleeve is in conductive contact with the corresponding peripheral conductor and a first length exists between the coupled conductive sleeve of a first conductor of the plurality of peripheral conductors and the proximal end of the elongate body of the lead, and a second length exists between the coupled conductive sleeve of a second conductor of the plurality of peripheral conductors and the proximal end of the elongate body, the second length being greater than the first length;
• mounting a plurality of contact members and a corresponding plurality of insulator members onto a strut member such that each insulator member is positioned adjacent to a corresponding contact member of the plurality of contact members, the strut member including a lumen that defines a central longitudinal axis of the in-line connector;
• forming a junction between the coupled conductive sleeve of each conductor and the corresponding mounted contact member such that the proximal portion of each conductor extends along the strut member and across a gap between the proximal end of the elongate body of the lead and a distal end of the strut member;
• positioning the proximal portion of each of the conductors in a helical path between the proximal end of the elongate body and the distal end of the strut member;
• and
• forming a grip zone around the proximal portions of the conductors, between the proximal end of the elongate body and the distal end of the strut member.